powdered snow fail

i found out that if u stand in a powdered snow for too long u get damage... but when i wanted to troll my afk friend and i placed him in some powdered snow he didnt die, after about half an hour he went back onto his pc and saw what i did. he was alive and well but he didnt see his hearts untill he did die from a skeleton. i didnt know if it was the armour (full iron) or the gamemode (normal) but i dont think this is how its supposed to work. i hope u can fix this soon and that i helped u a lot with making this exiting and allready fun looking 1.17...